I have a couple of WW1 Bayonetes – the long ones. Condition not too bad, no rust but no sheaths for them. I guess there are still hundreds of them about and have no 'rarity' value.
My quandary Should I have them destroyed so there is no chance of them getting into the wrong hands, or 'sell' them off to some sort of military / collectable shop?
I would certainly look at getting them to dealer or collector. Too much historical stuff is being scrapped as it is.
Value depends on model (I assume it's a 1907), make, age and condition but likely to be in tens of pounds, not scrap value. You can buy scabbards on ebay but they won't let you sell the bayonet.
There's a very active group of bayonet collectors on the Great War Forum website in the Arms section. If you post good pics of yours – especially any markings – those folk might identify if there's anything special or collectable about them.
If you take them to a militaria shop to sell, pack them securely in a cardboard box, so they are not a danger to anybody in transit, a chance encounter with the police with them loose on the back seat of the car could get you into a lot of trouble. It might even be sensible to tell the shop you are bringing them for evaluation before travelling.